Hydraulic means



E. F. ALLEN HYDRAULIC MEANS Original Filed Ma 29. 1961 Oct. 4, 1966 [N VEN TOR. time [flu 6N 4 rrop/YEY United States Patent 3,276,059 HYDRAULIC MEANS Earle F. Allen, Norwell, Mass., assignor to Valentine E. Macy, Jr., New York, N.Y.

Original application May 29, 1961, Ser. No. 113,367, now Patent No. 3,203,513, dated Aug. 31, 1965. Divided and this application June 2, 1965, Ser. No. 470,290

2 Claims. (Cl. 1436) The present invention relates to an improved hydraulic drive and more particularly to an improved hydraulic drive and control system adapted for use with lift bridges and other structures or loads.

This application is a division of application Serial No. 113,367 filed May 29, 1961 now Patent No. 3,203,513 dated August 31, 1965.

The improved hydraulic drive and control system of the present invention has been found to be particularly useful with lift bridges such as the bascule type and the following description is of a preferred embodiment of the use of the invention on such a bridge. It is clear that the invention is applicable in other uses where similar problems are faced in moving other structures or loads.

There are numerous short bridges on roads or tracks which extend over other waterways, roads, tracks or passageways wherein it would be desirable to have the bridge open to provide clearance. In many of these installations, however, the use of a movable span though desirable has been impracticable due to the relatively large investment required for such an installation. One result of this, for example, has been that the ever increasing network of highways has been responsible for the cutting off of access by water to many otherwise suitable boating areas. This has tended to create a shortage of commercial and recreational boating facilities adjacent to rivers, streams and coastal areas. There is thus an urgent need for a highway bridge which may be opened when necessary and which at the same time is relatively inexpensive, which has an operating mechanism which is simple, safe and rugged, and which is of the utmost reliability so that it may be operated by personnel inexperienced in such procedures so that the bridge does not require a regular attendant.

Previous bridges of relatively small size which have been designed to open in some cases have had only an impractical and time consuming fully manual control system or have had electromechanical systems with numerous sensitive and critical parts which have been su ject to failure from time to time and which have been operated only with difiiculty.

Accordingly, an object of the present invention is to provide an improved hydraulic drive and control system.

Another object of the present invention is to provide a rugged, relatively simple, safe and easily operated hydraulic drive and control system for a lift bridge or other structure or load.

Another object of the present invention is to provide a hydraulic drive system which requires only minimum maintenance.

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claim, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

FIG. 1 is a side elevational view of a lift bridge with the hydraulic drive of the present invention;

FIG. 2 is an enlarged sectional view of the pivotal connection between the hydraulic drive cylinders taken along line 2-2 on FIG. 1; and

3,275,059 Patented Oct. 4, I966 FIG. 3 is a side elevational view of the lift bridge of FIG. 1 shown in a partially and fully raised position.

FIGS. 1-3 illustrate a preferred embodiment of the hydraulic control for a lift bridge or similar structure. The embodiment illustrates several hydraulic cylinders interconnected to provide for a smooth powerful control where great loads are handled.

Two hydraulic cylinders and 101 are pivotally connected together in a line between a suitable pivot point 102 on a movable span 103 and a pivotal attachment on a fixed anchor 104. A third hydraulic cylinder 105 is pivotally attached at 109 to the pivotal coupling between the hydraulic cylinders 100 and 101. In this arrangement, hydraulic cylinder 105 is connected to provide a toggle arrangement so that a greatly multiplied mechanical force resulting from the toggle action is obtained as the piston rods 106 and 107 are drawn inwardly and the piston rod 108 of the hydraulic cylinder 105 is extended. This greatly multiplied force is particularly useful in this coupling as it is applied at the start of the lifting movement of span 103 where the greatest lifting force is required, This permits the bridge counterweight to be eliminated or reduced in size and weight. This arrangement may be operated by a control system as described in my Patent No. 3,203,513 to permit this bydraulic drive system to be effectively applied to lift bridge spans or to other similar structures. One or the other of the hydraulic cylinders 100' or 101 may be replaced by a solid linkage where the lifting power of three hydraulic cylinders is not required.

It will be seen that the present invention provides an improved hydraulic control system for lift bridges or other structures or loads. The hydraulic system combines dependability with relative simplicity by minimizing the number of moving parts and other parts. In addition, the present hydraulic drive and control system is particularly well suited for occasional use by unskilled operators due to the small number of controls required for operation.

As various changes may be made in the form, construction and arrangement of the parts herein without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

1. A hydraulic drive system for a movably mounted span of a lift bridge comprising the combination of a pair of linkage members pivotally connected together at one end of each, one of said members having its other end pivotally connected to the span, the other of said members having its opposite end pivotally connected to a fixed anchor adjacent to the span, one of said members comprising a first hydraulic cylinder, and a second hydraulic cylinder having one end pivotally coupled to the said pivotal coupling between the said members and having its opposite end pivotally coupled to an adjacent fixed anchor whereby said span is in its lowered position with the piston of said first cylinder extended and the piston of said second cylinder retracted and whereby said second hydraulic cylinder provides a toggle drive to raise the span as its piston is extended and the piston of the first hydraulic cylinder is retracted.

2. A hydraulic drive system for a movable span of a lift bridge comprising the combination of a pair of hydraulic cylinders pivotally connected together at one end of each, one of said cylinders having its other end pivotally connected to the span, the other of said cylinders having its opposite end pivotally connected to a fixed anchor adjacent to the span, and a third hydraulic cylinder having one end pivotally coupled to the said pivotal coupling between the other two cylinders and having its opposite end pivotally coupled to an adjacent fixed anchor whereby said span is in its lowered position with the pistons of said first and second cylinders extended and the piston of said third cylinder retracted and whereby said third hydraulic cylinder provides a toggle drive to raise the span as its piston is extended and the pistons of the said other hydraulic cylinders are retracted.

References Cited by the Examiner UNITED STATES PATENTS Wagner 214--77 Eakin 214--77 Rodgers 14-71 Lovell 1436 X JACOB L. NACKENOFF, Primary Examiner. 

1. A HYDRAULIC DRIVE SYSTEM FOR A MOVABLY MOUNTED SPAN OF A LIFT BRIDGE COMPRISING THE COMBINATION OF A PAIR OF LINKAGE MEMBERS PIVOTALLY CONNECTED TOGETHER AT ONE END OF EACH, ONE OF SAID MEMBERS HAVING ITS OTHER END PIVOTALLY CONNECTED TO THE SPAN, THE OTHER OF SAID MEMBERS HAVING ITS OPPOSITE END PIVOTALLY CONNECTED TO A FIXED ANCHOR ADJACENT TO THE SPAN, ONE OF SAID MEMBERS COMPRISING A FIRST HYDRAULIC CYLINDER, AND A SECOND HYDRAULIC CYLINDER HAVING ONE END PIVOTALLY COUPLED TO THE SAID PIVOTAL COUPLING BETWEEN THE SAID MEMBERS AND HAVING ITS OPPOSITE END PIVOTALLY COUPLED TO AN ADJACENT FIXED ANCHOR WHEREBY SAID SPAN IS IN ITS LOWERED POSITION WITH THE PISTON OF SAID FIRST CYLINDER EXTENDED AND THE PISTON OF SAID SECOND CYLINDER RETRACTED AND WHEREBY SAID SECOND HYDRAULIC CYLINDER PROVIDES A TOGGLE DRIVE TO RAISE THE SPAN AS ITS PISTON IS EXTENDED AND THE PISTON OF THE FIRST HYDRAULIC CYLINDER IS RETRACTED. 